With the wide-spread promulgation of USB standard, portable electronic devices having a connector complying with the USB standard have been gaining popularity in the market because of the ease of use and low cost of such connectors. Typically, a portable electronic device (e.g., a flash memory card, a digital camera, etc.) has a male USB connector, which may be plugged into a female USB socket provided by other portable or non-portable electronic devices, such as personal computers (PCs), personal digital assistants (PDAs), game consoles, etc. The male USB connector may also be simply referred to as a USB connector. A variety of external package case types have been developed for these portable electronic devices to protect their USB connectors. For example, a USB flash memory card typically uses surface mount technology (SMT) to assemble a printed circuit board assembly (PCBA) with an external package case for protecting the electronic components on the PCBA as well as to add esthetic value to the USB flash memory card. The external package case of most conventional USB memory cards (also referred to as USB memory sticks) generally has a protective cap detachably coupled to the main body of the package case. The protective cap (also simply referred to as the cap) is utilized to cover, and hence, to protect a male USB connector (or simply referred to as a USB connector) from mechanical and/or electrical damages. The protective cap is typically detached from the main body when the conventional USB memory card is in use, thus making it easy to lose the cap as users of the USB memory card often forget putting the cap back onto the USB memory card.